Salamanders from Bar Harbor lab may one day help people regrow missing limbs

With the help of hot dog-sized alien-like pink salamanders, scientists at a Bar Harbor lab hope to uncover secrets about how humans can regrow their limbs and bodily organs.

Used for research at the Mount Desert Island Biological Laboratory, the axolotl, pronounced “aksuh-lottle”, has a strange ability to push back the legs or important parts of its retina, heart and brain, as well as other parts of his body. He is originally from Mexico.

If scientists in the lab can understand how the regenerative abilities of aquatic axolotl work, and if it can be translated into human medicine, it could one day pave the way for the regrowth of tissues that could be damaged by a heart attack or stroke. fire. , according to James Godwin, an assistant professor at the lab who also conducts immunology research a few miles away at the Jackson Laboratory.

“We know that in the animal kingdom regeneration is possible,” Godwin said, pointing to an axolotl living in a clear plastic tub filled with water on his desk. “The proof is in front of you. “

Godwin recently made a discovery on axolotl blood cells that could potentially help humans regenerate parts of their bodies. He tracked down a type of white blood cell called macrophages that help axolotls avoid developing scar tissue in their liver – where humans also produce macrophages in their very early stages of development.

Early in human embryonic development, however, white blood cell production moves from the liver to the bone marrow, Godwin said, which appears to allow the creation of scar tissue in humans.

Macrophages in axolotls are produced throughout their lives by their livers, which appear to help them regrow their limbs and organs.

The scar tissue that occurs when humans suffer damage to the heart or lungs, or if they are severely burned, is believed to be an inhibitor of healthy tissue regeneration, Godwin said. If scientists can figure out how to get humans to continue producing macrophages from their livers as they age, it could allow humans to grow back damaged heart or lung tissue, or maybe even a finger or an ear one day, or even an entire member.

James Godwin, a scientist at the Mount Desert Island Biological Laboratory, examines water trays containing living salamanders called axolotls at the Bar Harbor laboratory on Thursday, December 9, 2021. Godwin recently made a discovery in blood cells of axolotls that could one day help humans grow back damaged tissue or missing limbs. Credit: Bill Trotter / BDN

“What’s really fascinating is that it really doesn’t have to be that way,” Godwin said of scar tissue growing on a wound, or even the need for a transplant. a donor in the event of organ failure. “This type of cell kind of blocks the healing process.”

In his research, Godwin found a way to temporarily block the production of macrophages from an axolotl in his liver, and when the axolotl lost a limb, it developed scar tissue instead of regrowing the limb. He said he was then able to restore the production of axolotl macrophages in his liver, and after the scar tissue was manually cut, the limb grew back.

Godwin said it is far too early in his research to know if such a treatment is possible on a human level. He noted that injectable patches being developed by other biomedical researchers that could help heart attack victims alleviate damage to their heart could also be a method of delivery for regenerative medicine.

If the chemical method he used to turn off hepatic macrophage production in axolotls can be reversed and applied to humans, Godwin said, this application might be possible with the same technology.

“We just need to know what to fill the patches with,” he said. “I think the future is optimistic in this regard.”

Godwin’s research is just one of the ways researchers at MDI Bio Lab are trying to learn more about how examples of regeneration or longevity in other organisms might be applicable to human medicine. These include studies on zebrafish, which can quickly grow back their tail with the help of drugs, and a type of small worm called C. elegans which, with genetic alterations, can live 5 times longer than it does. normally would. Last year, the lab also hired Prayag Murawala, who is also studying regeneration in axolotls.

About Hector Hedgepeth

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